Lock alarm structure

ABSTRACT

A lock and alarm structure incorporating a signal-generating device within a casing which is adapted for mounting on a closure member. A bolt housing is resiliently mounted in said casing and slidably receives a bolt. The bolt housing is mounted to pivot on the bolt and the bolt is formed with a resilient sidewall to permit the bolt housing to pivot on its mounting. A switchactuating lever is pivotally mounted on the bolt housing and extends through an opening in the casing such that relative movement between the intermediate portion of the bolt housing and the casing, upon pivoting of the bolt housing, will actuate the signal-generating device. The switch lever is positioned adjacent the bolt and is not easily accessible.

United States Patent 72] inventor Paul Maddison Hawkins Afton Township, Washington County, Minn. [21] Appl. No. 49,826 [22] Filed June 25, 1970 [45] Patented Nov. 23,1971 [73] Assignee Minnesota Mining and Manufacturing Company Saint Paul, Minn.

[54] LOCK ALARM STRUCTURE 4 Claims, 5 Drawing Figs.

[52] US. Cl 340/274, 70/441, 70/451, 200/44, ZOO/61.64, 340/276 [51] int. Cl G08b 13/06, E05b 45/00 [50] Field of Search 340/274, 276; 200/44, 61.64; 61.67; 70/451, 441, 416; 292/264, 63

[56] References Cited UNITED STATES PATENTS 2,730,970 1/1956 Martin 70/451 Primary Examiner-John W. Caldwell Assistant E.\'aminer l. Michael Bobbitt Attorney-Kinney, Alexander, Sell, Steldt & Delahunt ABSTRACT: A lock and alarm structure incorporating a signal-generating device within a casing which is adapted for mounting on a closure member. A bolt housing is resiliently mounted in said casing and slidably receives a bolt. The bolt housing is mounted to pivot on the bolt and the bolt is formed with a resilient sidewall to permit the bolt housing to pivot on its mounting. A switch-actuating lever is pivotally mounted on the bolt housing and extends through an opening in the casing such that relative movement between the intermediate portion of the bolt housing and the casing, upon pivoting of the bolt housing, will actuate the signal-generating device. The switch lever is positioned adjacent the bolt and is not easily accessible.

LOCK ALARM STRUCTURE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a security system and more particularly to a lock alarm arrangement permitting itsuse in connection with a closure member which swings either direction relative to its jamb whereby an attempted unauthorized entry utilizing force will cause relative movement between the jamb and the closure member and such movement will actuate the alarm through a single switch lever.

2. Description of the Prior Art Prior devices are known in the patent art for causing an alarmto be actuated upon a force being applied to a resiliently mounted lock element. Patents disclosing such devices include U.S. Pat. Nos. 3,406,386 and 3,444,546, issued to the applicant of this invention together with another example such as U.S. Pat. No. 2,730,970. While each of these devices teach the mounting of a casing for pivotal movement which will cause an alarm to be actuated these patents do not suggest how the casing may be mounted such that a force applied thereto in the opposite direction will have the same effect. One patent which provides for the actuation of the alarm with pressure applied to the locking element in either direction is U.S. Pat. No. 2,818,475 wherein the body of the bolt is centered in the casing and slidable with respect to two opposed springs. Functionally the structure of U.S. Pat. No. 2,818,475 is similar to the present invention but the manner of achieving the result was not desirable and presented a problem since the movement of the bolt was restricted by the washers bearing against the opposed sides of the bolt under the force of the springs. Further, the switch or alarm-actuating means cannot be silenced unless the lock is disassembled.

It is thus an object of the present invention to provide a strong locking mechanism which includes an alarm-actuating mechanism actuated to generate an alann in the event of an attempted forcible entry.

It is a further object of the present invention to provide an alarm lock structure having a freely slidable bolt mounted in a movable housing supported within a casing fixed to the closure member.

It is a further object of the present invention to provide a switch operator connected to the bolt housing and movable therewith to actuate the switch when sufficient force is applied against the closure member to cause movement of the bolt housing. The switch operator is also positioned to be accessible when the door is in the open position to permit the testing of the alarm mechanism and to permit the alarm to be interrupted when the door has been opened in an authorized manner. The availability or accessibility of the switch operator is not however convenient or easily located by one who may be attempting the unauthorized entry and will not reopen the contacts when the pressure of the attempted entry is removed.

SUMMARY OF THE INVENTION The alarm lock of the present invention comprises a casing adapted to be mounted by a base plate on a closure member and a bolt-receiving casing adapted for mounting on a cooperating closure member. A bolt housing is mounted within the casing for movement in a direction away from the casing and movement at one end is restrained by a compression spring bearing against the housing to urge the same toward the casing. A bolt is slidably mounted in the housing and extends from the end of the housing opposite the end mounted on the casing through a wall opening at one end of the casing which opening affords a fulcrum to urge the housing against the spring mounting. The bolt is also provided with a resiliently mounted sidewall positioned intermediate its length to be located at the wall opening when the bolt is in its extended, locked position. In this position a force applied in a direction to move the casing away from the bolt housing and pivot the housing about the spring mounting will be resisted by the resiliently mounted sidewall. The application of a force greater than the force that may normally be applied against a door to test the lock but less force than that at which the lock, closure members or fasteners for the same will yield and/or break will cause movement of the sidewall. A signal energizing device including a fixed contact and aswitch-actuating lever is aligned with the bolt housing and extends along its length. The switch lever has a conductive member forming the other switch contact attached thereto near one end, the other end is positioned in a portion of the wall opening supporting the bolt, and the lever is pivotally mounted intermediate its ends like a lever of the first class to move its contact in response to movement of the opposite end away from an edge of the opening. The lever responds as a second class lever and is fulcrumed, at the opening in the casing when the bolt housing is moved relative to the casing. The movement of the housing results by it being fulcrumed at the casing opening or pivoting at the mounted end. The end of the switch lever supporting the contact is resiliently held in a normally open position but upon movement to the closed circuit position it is resiliently retained in this closed position until the lever is pivotally operated independent of any movement of the lock structure.

DESCRIPTION OF THE DRAWING An illustrative embodiment of the present invention is described herein and shown in the accompanying drawings wherein:

FIG. 1 is a fragmentary plan view with parts broken away to show parts located interiorly of the lock alarm device;

FIG. 2 is a horizontal sectional view substantially through the longitudinal center of the lock alarm of FIG. 1;

FIG. 3 is a detailed sectional view showing one end of the switch lever and taken approximately along the line 3-3 in FIG. 1;

FIG. 4 is an end elevational view of the lock alarm of FIG. I; and

FIG. 5 is an elevational view of the bolt with a portion broken away to shown the interior thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, there is shown in FIG. 1 a first closure member 7 which may take the form of a door which is movably mounted relative to a second closure member 9 which may take the form of a door frame or jamb 9. The member 7 may move either direction from the position shown to permit passage therethrough but in the embodiment of the closure shown the door 7 is movable downward as shown in FIG, 1 to move the door to an open position.

On the inner surface of the door 7 is the lock alarm generally designated 10. The lock alarm comprises a casing including a mounting frame in the form of a shallow tray 12 which is mounted on the inner face of the door. The tray has a base plate 13 away from which extend three sidewalls l4, l5, and I6, and an end wall 17. Positioned over and corresponding generally; to the shape of the end wall which serves to trim the lock alarm structure and provides a cavity for a switch arm.

The casing for the lock alarm also includes a decorative I cover plate 20 which is secured to the tray 12 by suitable fastening means including screws 21 and 22. The cover 20 has a front face 24 formed with an enlarged rectangular opening 23 (see FIGS. 2 and 4). The opening 23 extends generally from one end of the front face 24, the end wall 17 and the edge of the closure 7, toward the opposite end on which is formed a grill structure to be positioned over the speaker in a self-contained lock-alarm structure.

Mounted within the casing and for movement against a spring is a bolt-receiving housing 25. The housing 25 is mounted for movement in a direction away from the base plate and the closure member. The housing 25, in its normal position, is aligned and generally parallel with the base plate of the casing and comprises a generally rectangular-shaped adjacent the end 17 is a face plate 18 k frame having a first hollow portion 26 rectangular in section in which is received a bolt 27. The bolt 27 has an elongated body with generally rectangular faces disposed normally parallel with the base plate and is of the dead-bolt type and slides freely within the housing 25 under the control of a bolt-actuating mechanism which includes a link 29 pivotally secured to the body of the bolt by a pivot pin 30. The other end of the link 29 is pivotally connected to a crank arm 31 secured to a thumbtum pin 32 which is rotatably mounted in the housing 25 in an upper generally rectangular hollow anchor-receiving portion 34. A decorative plate 33 covers the exposed surface of anchor portion 34 of housing 25. Rotation of the thumb-turn pin 32 rotates the crank arm 31 to cause oscillation of the link 29 for extending and retracting the bolt 27. The link 29 and thumb-turn 32 may also be rotated by the operation of a cam 35.having an eccentric pin 36 which cam 35 is driven from a spindle 37 connected to and operated by rotation of the plug of a conventional pin-tumbler cylinder lock assembly 39.

Either the thumb-turn 32 or cylinder lock 39 may be operated to move the bolt 27 to the extended position as shown in the drawing or to retract the bolt 27 into the boltreceiving housing 25. In the extended position the bolt 27 crosses the parting line between the closure member 7 and 9 and extends out of the housing 25 at one end through a rectangular opening formed in the end wall 17 of the casing 12 and the corresponding opening in the plate 18. In its extended position the bolt 27 is received in an opening in a casing 44 received and secured to the closure member 9. Secured to the casing 44 is one end of a flexible anchor link such as the chain 45 having at its other end a removable anchor 46 which cooperates with a slot 47 in the anchoring portion 34 of the bolt-receiving housing 25. The anchor member 46 thus secures by means of the chain 45 the bolt-receiving housing 25 to the casing 44 to secure the closure members 7 and 9 together but permitting some relative movement therebetween.

The bolt-receiving housing 25 is mounted in a manner to permit relative movement between the housing 25 and the casing 12 against the bias of a spring urging the housing to a normal position in alignment with the casing. The housing 25 is positioned at one end by the bolt 27, a part of which is always positioned in the opening in the end wall 17, and the opposite end rests upon a pedestal 49 against which it is urged and held by biasing means such as a pair of helical springs 50 (only one of which is shown) which are held in place by bolts 51 extending through the springs and a plate forming the housing 25. Upon a predetermined force being applied against the closure member 7 to move it in an upward direction (as shown in FIGS. 1 and 2) the bolt 27 will be fulcrumed in the plate 18 at the edge 52 to raise the housing 25 against the bias of springs 50. The housing can also pivot at the end mounted by the bolts 51 as the closure member 7 and casing (including its end wall 17 and plate 18) move downward from the position shown in H08. 1 and 2. This movement is restricted a slight amount by the springs 50 but primarily by a resiliently mounted sidewall in the face of the bolt 27 opposite the base plate 13 and aligned with the end wall 17 and plate 18 when the bolt is in its extended locked position.

The resiliently mounted sidewall is formed in the bolt 27 by forming a transverse slot 55 in one face of the body of the bolt 27. A plate 56 is positioned in the slot 55 to have the outer face flush with the face of the bolt. The plate is held by fasteners such as the three rivets 57, the ends of which are countersunk in the plate and the opposite side of the bolt, and compression springs 59 which are positioned about the rivets 57 and which are placed between the bolt and the plate urging the plate to its position flush with the side of the bolt. When the member 7 moves in a downward direction the bolt 27 moves relative to the rivets 57 compressing the springs 59 and the slot 55 moves along and over a portion of the end wall 17.

Upon movement of the bolt housing 25 relative to the casing against the bias of the springs, either 50 or 59, an alarm signal is produced which may be an audible signal resulting from the closing of the circuit to a sound generator which emits an audible sound through a speaker 60 or by merely closing a switch which energizes a remote signal generator or operates another signalling system. This signal is produced by a switch including a pair of contact which are closed by the operation of a switch lever 61. The lever 61 normally lies in a position as shown in the solid lines in FIG. 1 aligned with the bolt housing when the same is in its normal position. The lever 61 has one end extending through an opening 62 in the end wall 17 and this end does not extend beyond the face of the plate 18. The lever 61 is pivotally mounted intermediate its ends on a pin 64 secured to the bolt housing 25. On the opposite end 65 the lever is provided with a conductive member 66 which is one of the switch contacts and which is shaped to conform to the shape of the lever 61. The lever 61 has opposed ribs on the end 65 which result in a shape in section corresponding generally to that of a figure 8 as shown most clearly in FIG. 3. The end 65 of the lever 61 is retained in its normal position by the resilient flanges of a second fixed contact 69 which contact is generally U-shaped in section and has flanges which grasp the end portion 65 to maintain the contacts 66 and 69 normally in an open position and which upon movement of the lever 61 will flex to permit such movement and will engage the contact 66 to hold the lever and contacts in a closed position. In the normal position the contacts are separated by an insulative strip 67 which is positioned between the contact 66 on the end of the lever 61 and the blight of the contact 69 (see FIG. 3). The contacts 66 and 69 are connected with a suitable electrical circuit to energize the speaker 60 shown in the illustrated embodiment. The circuit may be supported within the casing and take the form of a printed circuit with the various electrical components.

It will thus be seen that movement of the bolt housing 25 as described above causes the lever 61 to act as a second class lever and be fulcrumed about the end extending through and contacting an edge of the opening 62 in the end wall 17 (see FIG. 1). As the housing moves sufficiently to move the pin 64 from the solid line position of FIG. 1 to the dotted line position thereof the end 65 of the lever will move from its normal contact open position to a raised operative contact closed position. The movement of the end 65 against the bias of the flanges on the contact 69 makes the switch actuation positive and when the flanges 69 engage the contact 66 they hold the contacts closed and the lever in the circuit closed position. This circuit will remain closed until such time as the lever is pivoted about the pin 64 by engagement and movement of the end of the lever in the opening 62 back toward the position shown in FIG. 1. Movement of the pin 64 to afford the movement of the lever 61 is afforded whether the closure member 7 moves upwardly or downwardly as shown in FIGS. 1 and 2 against either the biasing force of springs 50 or that of springs 59.

What is claimed is: v

1. A lock-alarm structure for doorlike closures comprising a casing having a base plate for mounting said casing on a door and having an end wall formed with an opening for supporting a bolt,

a signal energizing device enclosed by said casing and including a fixed switch contact supported on said base plate,

a bolt housing positioned within said casing and aligned at one end with said wall opening, said bolt housing being yieldably mounted to said casing at its opposite end for movement relative to said base plate upon application of a force to said housing,

a bolt positioned in said housing and slidable in said housing for movement relative to said housing and through said wall opening to a locking position and for retraction from said locking position, said bolt being fulcrumed in said wall opening when force is applied thereto to place a force against said housing, and

an elongate lever pivotally mounted intermediate its ends to said bolt housing, said lever having one end extending into said wall opening and normally engaging an edge thereof and having a conductive element on its opposite end, said conductive element being normally positioned in spaced relation to said fixed contact and movable into engagement therewith upon movement of said bolt housing to actuate said signal-energizing device.

2. A lock-alarm structure according to claim 1 wherein said bolt is formed with a resiliently mounted sidewall which permits movement of the bolt relative to said sidewall and in a direction along said end wall, said bolt comprising a generally elongated rectangularly shaped body having a transverse slot in one face thereof intermediate its ends and adjacent said wall opening when said bolt is in its extended position, a plate positioned in said slot generally flush with said one face, spring means positioned in said slot to resist movement of said plate in said slot, and fastening means slidable relative to said bolt for retaining said plate and spring means in said slot.

3. A lock-alarm structure according to claim 2 wherein said slot is formed in said bolt on the face thereof opposite said base plate.

4. A lock-alann structure for doorlike closures comprising a casing having a base plate for mounting said casing on a door and having an end wall perpendicular to said base plate and formed with an opening for supporting a bolt,

a signal-energizing device enclosed by said casing and including a fixed switch contact supported on said base plate,

a bolt housing positioned within said casing and aligned at one end with said wall opening, said bolt housing being mounted to said casing at its opposite end for movement relative to said base plate upon application of a force to said housing,

a bolt positioned in said housing and slidable in said housing for movement relative to said housing and through said wall opening to a locking position and for retraction from said locking position, said bolt comprising a generally elongated rectangularly shaped body having opposed faces positioned normally in a plane generally parallel to said base plate and having a transverse slot in one face thereof intermediate its ends and adjacent said wall opening when said bolt is in its extended position relative to said housing, a plate positioned in said slot generally flush with said one face, spring means positioned in said slot to resist movement of said plate in said slot, and fastening means slidable relative to said bolt for retaining said plate and spring means in said slot, and

an elongate lever pivotally mounted intermediate its ends to said bolt housing, said lever having one end extending into said wall opening and normally engaging an edge thereof and having a conductive element on its opposite end, said conductive element being normally positioned in spaced relation to said fixed contact and movable into engagement therewith upon movement of said bolt housing when a force is applied against said casing to move it relative to said bolt to actuate said signal-energizing device. 

1. A lock-alarm structure for doorlike closures comprising a casing having a base plate for mounting said casing on a door and having an end wall formed with an opening for supporting a bolt, a signal energizing device enclosed by said casing and including a fixed switch contact supported on said base plate, a bolt housing positioned within said casing and aligned at one end with said wall opening, said bolt housing being yieldably mounted to said casing at its opposite end for movement relative to said base plate upon application of a force to said housing, a bolt positioned in said housing and slidable in said housing for movement relative to said housing and through said wall opening to a locking position and for retraction from said locking position, said bolt being fulcrumed in said wall opening when force is applied thereto to place a force against said housing, and an elongate lever pivotally mounted intermediate its ends to said bolt housing, said lever having one end extending into said wall opening and normally engaging an edge thereof and having a conductive element on its opposite end, said conductive element being normally positioned in spaced relation to said fixed contact and movable into engagement therewith upon movement of said bolt housing to actuate said signalenergizing device.
 2. A lock-alarm structure according to claim 1 wherein said bolt is formed with a resiliently mounted sidewall which permits movement of the bolt relative to said sidewall and in a direction along said end wall, said bolt comprising a generally elongated rectangularly shaped body having a transverse slot in one face thereof intermediate its ends and adjacent said wall opening when said bolt is in its extended position, a plate positioned in said slot generally flush with said one face, spring means positioned in said slot to resist movement of said plate in said slot, and fastening means slidable relative to said bolt for retaining said plate and spring means in said slot.
 3. A lock-alarm structure according to claim 2 wherein said slot is formed in said bolt on the face thereof opposite said base plate.
 4. A lock-alarm structure for doorlike closures comprising a casing having a base plate for mounting said casing on a door and having an end wall perpendicular to said base plate and formed with an opening for supporting a bolt, a signal-energizing device enclosed by said casing and including a fixed switch contact supported on said base plate, a bolt housing positioned within said casing and aligned at one end with said wall opening, said bolt housing being mounted to said casing at its opposite end for movement relative to said base plate upon application of a force to said housing, a bolt positioned in said housing and slidable in said housing for movement relative to said housing and through said wall opening to a locking position and for retraction from said locking position, said bolt comprising a generally elongated rectangularly shaped body having opposed faces positioned normally in a plane gEnerally parallel to said base plate and having a transverse slot in one face thereof intermediate its ends and adjacent said wall opening when said bolt is in its extended position relative to said housing, a plate positioned in said slot generally flush with said one face, spring means positioned in said slot to resist movement of said plate in said slot, and fastening means slidable relative to said bolt for retaining said plate and spring means in said slot, and an elongate lever pivotally mounted intermediate its ends to said bolt housing, said lever having one end extending into said wall opening and normally engaging an edge thereof and having a conductive element on its opposite end, said conductive element being normally positioned in spaced relation to said fixed contact and movable into engagement therewith upon movement of said bolt housing when a force is applied against said casing to move it relative to said bolt to actuate said signal-energizing device. 